Patent: 9,339,510

Summary for Patent: 9,339,510

Title:	Azepane derivatives and methods of treating hepatitis B infections
Abstract:	Provided herein are compounds useful for the treatment of HBV infection in a subject in need thereof, pharmaceutical compositions thereof, and methods of inhibiting, suppressing, or preventing HBV infection in the subject.
Inventor(s):	Hartman; George D. (Landsdale, PA), Kuduk; Scott (Harleysville, PA)
Assignee:	NOVIRA THERAPEUTICS, INC. (Doylestown, PA)
Application Number:	14/856,761
Patent Claims:	see list of patent claims

US 9,339,510 (HBV) Patent Landscape and Claim-Validity Analysis

What does US 9,339,510 claim?

US Patent 9,339,510 claims methods for treating hepatitis B virus (HBV) infection by administering a “compound of Formula Va” (or salts), including broad substituent-defined variants, optionally in combination with standard-of-care HBV agents (polymerase inhibitors/nucleos(t)ides), immunomodulators (interferons), innate immune agonists (TLR-7 agonists), viral entry/maturation inhibitors, and HBV vaccines. The patent also includes method variants that require viral load reduction to “undetectable” and include specific example embodiments (claims 13-20) that narrow substituent classes and identify particular structures.

Core independent claim structure (Claim 1)

Claim 1 is a treatment method:

• Administer a therapeutically effective amount of a Formula Va compound (or salt) to an individual with HBV.
• Formula Va has:
  • R¹: halo, OH, C1-C6 alkyl, or O-alkyl (C1-C6), with alkyl optionally substituted 1-3 times by halo or OH
  • R²: same substitution logic as R¹
  • x: 2 or 3
  • Cy: a bicyclic/aryl scaffold as depicted in the patent’s figure (“Cy is ##STR00751##”)
  • R¹¹: OH, halo, C1-C6 alkyl, OC(O)CH3, or H2PO4; at least one R¹¹ is ##STR00752##
  • n and m: 1, 2, or 3

The claim is written to capture a large chemical universe under a scaffold, while relying on: 1) substituent class definitions (halo/OH/alkyl/O-alkyl), and
2) a restricted set of permissible “R¹¹” functionalities including a specific at-least-one condition.

Combination/adjunct claims (Claims 2-11, 9-11)

Claim 2 adds “at least one additional therapeutic agent” chosen from a wide list, including:

• HBV polymerase inhibitors
• immunomodulatory agents
• pegylated interferon
• viral entry inhibitor
• viral maturation inhibitor
• BAY 41-4109 (a well-known HBV-targeting small molecule in older literature)
• reverse transcriptase inhibitor
• cyclophilin/TNF inhibitor
• TLR agonist
• HBV vaccine
• combinations

Claim 3 narrows the “additional agent” to a reverse transcriptase inhibitor selected from a long catalog of nucleoside analogs (zidovudine, lamivudine, entecavir, tenofovir, adefovir, ribavirin, etc.).

Claim 4 narrows to a TLR-7 agonist, listing:

• SM360320
• AZD 8848

Claims 5-8 narrow interferons:

• interferon alpha/beta/lambda/gamma
• then to interferon-alpha-2a, alpha-2b, alpha-n1
• then to pegylated forms, including PEGASYS (pegylated interferon-alpha-2a)

Claims 9-10 add HBV vaccine types:

• RECOMBIVAX HB, ENGERIX-B, ELOVAC B, GENEVAC-B, SHANVAC B

Viral-load-based method limits (Claims 11-12)

Claim 11 is a method that:

• reduces HBV viral load by administering the Formula Va compound
• optionally “alone or in combination with a reverse transcriptase inhibitor”
• and further administering an HBV vaccine

Claim 12 further narrows Claim 1 by adding:

• monitoring HBV viral load
• method duration such that “HBV virus is undetectable.”

Narrowing by substituent class and explicit structures (Claims 13-20)

Claims 13-14 add substituent restrictions:

• Claim 13: each R¹ is halo
• Claim 14: each R² is halo or C1-C6 alkyl with alkyl optionally substituted 1-3 times with halo

Claims 15-20 identify specific compound embodiments by showing additional “##STR…” structure blocks and specifying selection among them.

Net effect: independent coverage is scaffold-and-substituent broad; dependent claims add explicit structures and specific marketed agents (pegylated interferon-alpha-2a, vaccines, named TLR-7 agonists).

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How broad is the chemical claim coverage, and where is it fragile?

Breadth drivers

1) “R¹” and “R²” are class-based rather than enumerated single compounds.
Halo/OH/alkyl/O-alkyl definitions can capture many variants.

2) x = 2 or 3 is a minor ring-position flexibility.

3) n and m are each 1-3: multiplies possible regio/atom counts within the defined scaffold.

4) R¹¹ allows multiple functional groups, including OH, halo, alkyl, acetate ester (OC(O)CH3), and phosphate (H2PO4), plus a condition that at least one R¹¹ is the specific depicted moiety.

Fragility points (likely weak spots in validity)

1) The claim does not state mechanism, target, or binding.
It is purely treatment-method and structure-defined. That invites obviousness arguments based on prior art HBV therapies plus known chemical scaffolds.

2) Combination claims rely on known HBV standards.
The “additional therapeutic agent” list includes standard care classes and named agents. If the Formula Va compound itself is known (or close), the incremental “use with” known HBV agents can be attacked as obvious.

3) The “undetectable” limitation (Claim 12) is a functional endpoint.
It can be attacked for indefiniteness or as not limiting because “undetectable” depends on assay sensitivity. The claim still narrows duration (“for a period of time such that”), but the patent text you provided does not tie it to a specific assay threshold or detection technology.

4) Chemical specificity is partly shifted to the figures (“##STR…”).
In many litigations, structure-defined limitations require consistent claim construction with drawings/embodiments. If “Cy” or the “at least one R¹¹ is ##STR…” condition depends on ambiguous depiction, this can weaken enforcement.

5) Claims 15-20 are likely the most enforceable because they map to specific structures; claims 1-2 and 11 are typically where prior art overlap creates invalidity risk.

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How does the claim align with current HBV treatment paradigms?

The patent’s combination list is consistent with HBV regimens across time, but the framing is broad:

• Nucleos(t)ide reverse transcriptase inhibitors are standard:
  • lamivudine, entecavir, tenofovir, adefovir, emtricitabine, etc.
• Interferons and pegylated interferons are established:
  • PEGASYS is explicitly named.
• TLR-7 agonists have been explored:
  • AZD 8848 is a named compound in prior immune-activation programs.
• Vaccines are prophylactic but can appear in therapeutic contexts in older experimental combinations.

The claim set is therefore positioned to cover:

• a “drug + SOC class” strategy, and
• a “drug + immune activation (TLR/interferon) + vaccine” strategy.

For a validity attack, this matters: if the scaffold is not new or is only marginally modified from earlier literature, then pairing it with already-known HBV therapy classes often becomes the obviousness battleground.

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What is the patent landscape likely to look like around this scaffold?

Without the patent’s bibliographic data (assignee, filing date, and specification disclosure), the landscape can still be assessed based on typical HBV chemical and method-genus patterns:

1) Prior art overlap risk: “known nucleos(t)ides + known scaffolds”

Claim 2-4/5-8/9-10 incorporate widely used HBV agents by name or class. If Formula Va compounds are:

• disclosed in earlier publications as anti-HBV agents or close analogs, or
• disclosed as antiviral agents for other viruses,

then combinations could be attacked as obvious substitutions.

2) “At least one R¹¹ is ##STR00752##” suggests a specific pharmacophore

The “at least one” rule is a common drafting technique to preserve a medicinal chemistry core while allowing peripheral variation. This reduces the prior art search to whether earlier documents disclose:

• the same scaffold, and
• the same or similar “R¹¹” functionality.

3) TLR-7 agonist and interferon/vaccine combos are likely crowded

SM360320 and AZD 8848 are specific immune agonists. If those compounds have prior HBV therapeutic uses, then claim coverage may already exist in earlier immunotherapy patents or publications. A court will look for:

• earlier disclosures combining TLR-7 agonists with HBV therapies, and
• earlier vaccine-in-combination approaches for HBV.

4) Enforceability hinges on Claim 15-20 structure picks

Claims 15-20 map to specific “##STR…” compounds. In practice, those dependent claims often survive longer during litigation because:

• prior art must match a narrower structure (exact or very close),
• while Claim 1’s genus often becomes invalid as overly broad.

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Claim-by-claim: enforceability and vulnerability map

Claims 1, 11 (Genus treatment methods)

Strength: capture broad chemical variants under one scaffold, without requiring additional agent specificity (except claim 11 adds vaccine and reduces viral load).
Vulnerability: genus-obviousness and lack of distinguishing features if prior art discloses:

• the same or closely related Formula Va scaffold, and
• HBV treatment or antiviral use in a therapeutic method context.

Claim 2 (Any of a wide list of HBV adjunct agents)

Strength: broad combination coverage.
Vulnerability: “routine pairing” attack. With HBV, many adjunct agents are standard-of-care. If Formula Va is not strongly differentiated, this can collapse under obviousness.

Claim 3 (Reverse transcriptase inhibitor list)

Strength: enumerates common nucleoside/nucleotide analogs.
Vulnerability: many of these are old; the claim may be treated as an obvious selection of known HBV drugs once the Formula Va concept is known.

Claim 4 (TLR-7 agonists by name)

Strength: more specific, improves enforceability vs generic “TLR agonist.”
Vulnerability: if earlier documents disclose AZD 8848 or SM360320 in HBV regimens, this claim may be duplicative.

Claims 5-8 (Interferons; PEGASYS)

Strength: PEGASYS is explicit; pegylated IFN use is well established.
Vulnerability: pairing a new compound with known IFN regimens is often an obviousness target.

Claims 9-10 (Vaccines)

Strength: lists specific vaccine brands.
Vulnerability: HBV vaccine as a therapeutic combination agent is less standardized than nucleos(t)ides/interferon. If the earlier record supports therapeutic vaccination, validity weakens; if not, then these claims might be distinctive but may still be obvious in concept.

Claim 12 (“undetectable” endpoint)

Strength: functionally narrows method outcome.
Vulnerability: indefiniteness and non-limiting behavior if the detection standard is not defined in the claim text (assay thresholds vary).

Claims 13-14 (substituent class narrowing)

Strength: improves novelty and enforceability vs full genus.
Vulnerability: if earlier disclosures already focus on halo substitution patterns, novelty may erode.

Claims 15-20 (selected structures)

Strength: strongest for enforcement because they force closer structural matching.
Vulnerability: if earlier documents disclose these exact structures (or salts) for antivirals generally or HBV specifically, then they are direct prior art hits.

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Practical business assessment: what would an investor or R&D team look for next?

1) Determine how many earlier documents disclose “Formula Va” members

• If the scaffold or near-identical analogs are widely published with antiviral function, then the business case depends on whether:
  • HBV-specific method claims are still distinguishable, and
  • the “R¹¹ at least one ##STR00752##” requirement blocks close prior art.

2) Map the named adjunct agents to prior HBV combination disclosures

• AZD 8848, SM360320, PEGASYS, and the specific vaccines may each have their own prior combination literature or patent families.
• If those exist, the patent’s incremental value shifts back to the Formula Va compounds themselves.

3) Treat Claim 12 as a negotiable feature for freedom-to-operate

“Undetectable” is assay- and protocol-dependent. In licensing/FTO, the practical read is whether any competing regimen can plausibly argue it does not meet the “undetectable” condition as claimed.

4) Portfolio strategy: separate genus licensing from structure licensing

• Genus coverage (Claim 1/11) may face higher invalidity risk.
• Structure claims (15-20) may support more durable licensing positions.

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Key Takeaways

• US 9,339,510 is a structure-defined HBV treatment patent built on a broad Formula Va genus with class-based substituent variability (R¹, R², x, Cy, n/m, and an “at least one R¹¹ is ##STR00752##” constraint).
• The claims heavily integrate standard HBV adjunct classes and named agents (reverse transcriptase inhibitors, interferons including PEGASYS, TLR-7 agonists including AZD 8848/SM360320, and specific vaccines), which increases obviousness pressure if the Formula Va scaffold is not clearly differentiated in prior art.
• Enforceability is likely strongest in the specific embodiment selection claims (15-20) that map to particular structures, while genus claims (1/11) are the main invalidity battleground due to breadth and lack of mechanistic narrowing.
• Claim 12 introduces a functional endpoint (“undetectable”) that may narrow the method in enforcement but can also become a litigation and claim-construction fault line due to assay dependence.

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FAQs

1) What is the single biggest novelty lever in US 9,339,510?

The Formula Va chemical definition, especially the constraint that at least one R¹¹ is ##STR00752## while varying peripheral substituents.

2) Which claims are most likely to be attacked first in validity challenges?

Claims 1 and 11 because they are genus treatment methods with broad substituent classes and no mechanistic narrowing.

3) Do the combination claims expand novelty or mainly expand coverage?

They mainly expand coverage. In HBV, combining with known agents (nucleos(t)ides, interferons, TLR-7 agonists, vaccines) is often framed as routine selection for obviousness analysis.

4) Are the TLR-7 and PEGASYS-specific claims stronger than the generic interferon/TLR claims?

Yes. Claims that name AZD 8848/SM360320 and PEGASYS are more constrained and typically more enforceable than broad class language, but they still face prior art risk if those agents are already disclosed in HBV therapeutic combinations.

5) Which parts of the claim set are most relevant for commercial licensing strategy?

Structure-selection claims (15-20) for durability, and adjunct-agent mapping (Claims 2-10) for competitive positioning and FTO alignment.

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References

[1] US Patent 9,339,510. “Method of treating an HBV infection” (claims as provided).

Details for Patent 9,339,510

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Merck Sharp & Dohme Llc	RECOMBIVAX, RECOMBIVAX HB	hepatitis b vaccine (recombinant)	Injection	101066	July 23, 1986		2035-09-17
Glaxosmithkline Biologicals	ENGERIX-B	hepatitis b vaccine (recombinant)	Injection	103239	August 28, 1989		2035-09-17
Pharmaand Gmbh	PEGASYS	peginterferon alfa-2a	Injection	103964	October 16, 2002		2035-09-17